The current authorization for all of these wars comes from the 2001 AUMF which specifies we are at war with al Qaeda and their affiliates. That is supported in 2016 by a statement from President Peace Prize and the NDAA 2012 which made it illegal to support any nation which provides any support to al Qaeda or their affiliates.

Trump attacked Syria last year this time in support of Tahrir al-Sham (part of al Nusra…formerly known as “al Qaeda in Syria”) and yesterday the IDF attacked the Syrian military in support of Jaysh al-Islam (part of al Nusra… formerly known as “al Qaeda in Syria”)

We live in BizarroWorld folks. Our leaders and our allies in the Middle East are actively supporting al Qaeda on a daily basis and we do nothing about it… except of course call people who point this out “fake news”